Louver construction for exhaust gas device

ABSTRACT

A louver construction especially suitable for packed exhaust gas mufflers, fibrous acoustic material comprises elongated openings defined by spaced lips which are formed in the wall of the gas flow tube to extend at substantially right angles to the wall and in a direction away from the fibrous material.

o Un ted States Patent 1 1 11 3,912,040 Balluff Oct. 14, 1975 LOUVER CONSTRUCTION FOR EXHAUST [56] References Cited GAS DEVICE UNITED STATES PATENTS [75] Inventor: Robert N. Balluff, Rives Junction, 2,527,052 10/1950 Beck et al. 181/35 C UX Mich. 3,263,772 8/l966 Irwin et a1 3,479,145 11/1969 Lcntii l8l/61X [73] Asslgneez Tenneco lnc., Racme, Wis. [22] Filed; Aug, 15, 1974 Primary ExaminerStephen J. Tomsky Assistant Examiner--.Iohn F. Gonzales [21] Appl' 497673 Attorney, Agent, or Firm-Harness, Dickey & Pierce Related US. Application Data {62] Division of SCI. No. 242,995, April 11, 1972, Pat. ABSTRACT 3-840'364 A louver construction especially suitable for packed exhaust gas mufflers, fibrous acoustic material com- [52] US. Cl 181/42; l38/l56; 181/35 C; prises elongated Openings defined by Spaced PS 2 181/ 5 5 which are formed in the wall of the gas flow tube to [5i Int. Cl. FOIN 1/04; Fl6L 9/00 extend at substantially right angles to the wall and i a [58] Field of Search l8l/4l, 42, 59, 47 R, 48,

l8l/57, 55, 50, 35 C; l38/l56 direction away from the fibrous material.

4 Claims, 8 Drawing Figures RELATED APPLICATION the shell 26 and also the downstream end of the tube 21. The upstream end of the shell 26 may be united to the tube'2l by means ofa transverse partition 33-which acts to close the upstream end of thebed 27. A flow This application is a division of my copending'lLS. -'distributing partition 35 may be mounted inside the application Ser. No. 242,995, filed Apr. ll, l972,now Patent n ,840,364. t V I BRIEF SUMMARY OF TIIEINv ENTIoN] It is the purpose of this invention to provide an i'rnproved louver construction for use with beds of nontube 21 and catalyst pellet flow controlling partitions 37 r nay be mounted inside the bed 27.

In operation, exhaust gas to be treated wille'nter' 'the i inlet opening 9 and flow along "the length of' the tube L211. It will then pass radially from the tube through the ",bed 27 and through the shell 26 into spaces 39 or 41 metallic particulate material, such as catalyst pellets or fibrous, acoustic packing, which will minimize losses of the material due to abrasion and give other advantages. This purpose is accomplished by forming the louvers with lips that extend outwardly of the walls of the bed to minimize the sharp edges that are presented to the particles and to minimize gas turbulance. f

DESCRIPTION O TI-IEDRAWINIGVSI FIG. 1 is a longitudinal cross-section through an illustrative' form of catalyst converter having-louvers embodying the invention;

FIG. 2 is across-section along the line 2 .2 of FIG.

DESCRIPTION OF THE INVENTION The catalyst converter 1 has an outer shell 3 which is preferably oval in cross-section and has an inlet header 5 closing one end and an outlet header 7 closing the other end, the headers being secured to the ends of the shell 3 in gas tight rolled joints 8. The inlet header 5 has an inlet opening 9 and located around it is a reinforcement pad 11 with threaded holes 13 whereby an inlet casting or exhaust pipe flange may be bolted to the converter to deliver exhaust gas through the opening 9. The outlet header 7 has an outlet opening 15 around which is a relatively thick reinforcement pad 17 with threaded opening 19 whereby an outlet casting or tailpipe flange may be secured to the converter 1 to carry gases away from it.

Inside of the shell 3 and in alignment with the inlet opening 9 is a perforated tube 21 which is rolled up from a blank 23 with opposite edges 24 of the blank being interlocked in a lock seam 25. A perforated shell 26 formed, like tube 21, from a rolled up sheet, surrounds the tube 21 and the space between the two comprises the catalyst bed 27 which, in actual use of the converter 1, is filled with suitable catalystpellets. As seen in FIG. 2, the shell 26 is concentric with the tube 21 but engages the oval shaped shell 3 along the minor diameter thereof as indicated at 28 whereby the outer shell supports the inner shell 26. The tube 21 is supon opposite sides of the shell 23 from which it can flow to a transverse chamber 43 at the downstream end of the converter which empties the gas into the outlet opening 15 through which it can flow away from the converter.

In accordance with this invention, the openings 45 in the tube 21, and preferably the openings 47 in the shell .26, are formed in a special way which is "best shown in FIGS. 3 to 5.. As can be seen, theopenings are each substantially rectangular in shape, substantially uniform in size, shape, and spacing, and areformed in rowsthat extend circumferen t ially withrespec't to the axisof the tube 21 or the axis of the shell 26. The holes in adjacent rows are staggered as indieatedin FIGS. 1

, and 3 and it is preferable. that the o'pen ing s in one row -;be;lon gitudinally aligned with the space between adjacent openings in the adjacent row as this minimizes the possibility of fracture or tearing of the metal. When the holes (or 47) are formed, the longitudinally extending edges are retained instead of being sheared out, one way of accomplishing this being by means of a lancing operation. They are bent in forming to extend at approximately right angles to the plane of the blank so that they appear as lips or ribs 51 and 53 on opposite sides of the opening. A smoothly contoured streamline appearance can be achieved, as indicated at 55 in FIG. 5, and it is apparent that the lips will function to direct the gas flowing through them to flow at substantially right angles to the plane of the opening.

FIGS. 6 through 8 show a slightly different form of hole for a blank 23'. In this form the holes are sheared or lanced out to have longitudinal side ribs or lips 151 and 153 to give a smoothly contoured opening as seen at 155. In this form the ends of the elongated holes 145 are rounded and provided with lips or ribs 157 and 159 that blend into the side lips 151 and 153. A slight split or part at 161 may be formed by the lancing or shearing operation in the lips 157 and 159 but the overall appearance and shape is rounded and streamlined. The holes 145 are preferably sized, spaced, and placed in the manner described for holes 45 and function in the same manner.

With the louver structure and arrangement described, the walls or grids (tube 21 and shell 26) are inherently strong since no material is removed in making the openings 45, 47, and 145 and the lips or ribs improve the strength of the wall, as compared with plain openings, so that sheet thickness limitations are not as critical. Thelips and contours direct flow substantially perpendicular to the wall to minimize gas turbulence and pressure losses as well as catalyst losses due to abrasion across sharp edges.

While the invention has been described and illustrated in connection with a catalyst bed, it is also of substantial value in ordinary packed mufflers where fibrous materials of various types are packed in a space or bed" around a louvered gas flow tube. In these mufflers the louvers may be formed as described herein and the lips preferably arranged to project away from the packing.

Modifications may be made without departing from the spirit and scope of the invention.

l claim:

1. An exhaust gas treating device comprising a housing having a bed of acoustic packing material, a gas flow conduit to conduct gas to the bed comprising a metal tube forming an inlet side of the bed and having a longitudinal seam extending along its entire length and parallel to the axis of the tube and a plurality of circumferential rows of holes in the tube openings into said bed, each row being transverse to the seam and axis of the tube and containing a plurality of spaced substantially rectangular holes having their long sides extending parallel to said seam and axis and having rounded ends, said holes being substantially identical in size and shape and the spaces between adjacent holes in each row being substantially identical, the holes in adjacent rows being staggered so that the holes in one row are longitudinally aligned with the spaces in the adjacent rows, each row being longitudinally spaced from the adjacent rows, and lips formed in the tube to define each of said long sides and said rounded ends and extending at substantially right angles to the tube and away from the bed to direct gas flowing through them into the bed at substantially right angles to the planes of the holes.

2. A gas flow conduit for use in an exhaust gas treating assembly or the like comprising a metal tube having a longitudinal seam extending along its entire length and parallel to the axis of the tube and a plurality of rows of holes in the tube, each row being transverse to the seam and axis of the tube and containing a plurality of spaced substantially rectangular holes having their long sides extending parallel to said seam and axis, said holes being substantially identical in size and shape and the spaces between adjacent holes in each row being substantially identical, the holes in adjacent rows being staggered so that the holes in one row are longitudinally aligned with the spaces in the adjacent rows, each row being longitudinally spaced from the adjacent rows, and lips formed in the tube to define each of said long sides and extending at substantially right angles to the tube to direct gas flowing through them at substantially right angles to the planes of the holes.

3. A conduit as set forth in claim 2 wherein said lips extend only along the longitudinal sides of the rectangular openings.

4. A conduit as set forth in claim 2 wherein said openings have rounded ends and rounded lips around said ends blending into said longitudinal side lips. 

1. An exhaust gas treating device comprising a housing having a bed of acoustic packing material, a gas flow conduit to conduct gas to the bed comprising a metal tube forming an inlet side of the bed and having a longitudinal seam extending along its entire length and pArallel to the axis of the tube and a plurality of circumferential rows of holes in the tube openings into said bed, each row being transverse to the seam and axis of the tube and containing a plurality of spaced substantially rectangular holes having their long sides extending parallel to said seam and axis and having rounded ends, said holes being substantially identical in size and shape and the spaces between adjacent holes in each row being substantially identical, the holes in adjacent rows being staggered so that the holes in one row are longitudinally aligned with the spaces in the adjacent rows, each row being longitudinally spaced from the adjacent rows, and lips formed in the tube to define each of said long sides and said rounded ends and extending at substantially right angles to the tube and away from the bed to direct gas flowing through them into the bed at substantially right angles to the planes of the holes.
 2. A gas flow conduit for use in an exhaust gas treating assembly or the like comprising a metal tube having a longitudinal seam extending along its entire length and parallel to the axis of the tube and a plurality of rows of holes in the tube, each row being transverse to the seam and axis of the tube and containing a plurality of spaced substantially rectangular holes having their long sides extending parallel to said seam and axis, said holes being substantially identical in size and shape and the spaces between adjacent holes in each row being substantially identical, the holes in adjacent rows being staggered so that the holes in one row are longitudinally aligned with the spaces in the adjacent rows, each row being longitudinally spaced from the adjacent rows, and lips formed in the tube to define each of said long sides and extending at substantially right angles to the tube to direct gas flowing through them at substantially right angles to the planes of the holes.
 3. A conduit as set forth in claim 2 wherein said lips extend only along the longitudinal sides of the rectangular openings.
 4. A conduit as set forth in claim 2 wherein said openings have rounded ends and rounded lips around said ends blending into said longitudinal side lips. 